be nice if user gets the image visibility case wrong

builder/openstack/image_config.go

@@ -2,6 +2,7 @@ package openstack
 
 import (
 	"fmt"
+	"strings"
 
 	imageservice "github.com/gophercloud/gophercloud/openstack/imageservice/v2/images"
 	"github.com/mitchellh/packer/template/interpolate"
@@ -9,8 +10,7 @@ import (
 
 // ImageConfig is for common configuration related to creating Images.
 type ImageConfig struct {
-	ImageName string `mapstructure:"image_name"`
-
+	ImageName       string                       `mapstructure:"image_name"`
 	ImageMetadata   map[string]string            `mapstructure:"metadata"`
 	ImageVisibility imageservice.ImageVisibility `mapstructure:"image_visibility"`
 	ImageMembers    []string                     `mapstructure:"image_members"`
@@ -36,11 +36,12 @@ func (c *ImageConfig) Prepare(ctx *interpolate.Context) []error {
 	// ImageVisibility values
 	// https://wiki.openstack.org/wiki/Glance-v2-community-image-visibility-design
 	if c.ImageVisibility != "" {
-		validVals := []string{"public", "private", "shared", "community"}
+		validVals := []imageservice.ImageVisibility{"public", "private", "shared", "community"}
 		valid := false
 		for _, val := range validVals {
-			if string(c.ImageVisibility) == val {
+			if strings.EqualFold(string(c.ImageVisibility), string(val)) {
 				valid = true
+				c.ImageVisibility = val
 				break
 			}
 		}